ESS1 4aa-calculating the age of rocks from various regions using radioactive half life (given its constituent elements, isotopes and rate of decay)and using those values to provide evidence for geological relationships between/among regions.
LS3 8c-recognizing patterns in molecular and fossil evidence, to provide a scientific explanation for Natural Selection and its evolutionary consequences.
National Standards:
Standard A- the ability to DO scientific inquiry
Standard D- ESS3-origin and evolution of the earth system
Context of Lesson:
This lesson will teach students about how the earth was formed and when and how the first forms of life developed. The points of the lesson are: 1) the age of the earth has been dated using radioactive isotopes, like uranium-238; 2) elements can be used to determine the changing composition of earth and the time that they were formed; 3) the earliest life-forms were single celled organisms that gave rise to other organisms through endosymbiosis
Opportunities to Learn:
Depth of Knowledge:
DOK-level 1: recall and reproduction of the age of earth and the procedure used to figure it out
DOK-level 1: recall and reproduction of plant and animal cell structure and function
DOK-level 3: connecting the state of prehistoric cells to current cells
DOK-level 2: interpret how penny lab represent the actions of radioactive isotopes
Prerequisite Knowledge:
-"Big Bang" theory
-rock cycles
-gravitational pull
-cellular structures and functions
Plans for Differentiating Instruction
Bodily-kinesthetic: Penny lab is a hands-on activity (shaking the box, picking up pennies, using more than a pencil and paper)
Visual: Diagram of prehistoric cells next to modern cells so students can see the similarities and differences
Accommodations and modifications
Students with poor vision will have priority seating for viewing the overhead. Students with documented learning disabilities will receive the handouts one class day before the lesson.
Environmental factors
The classroom is set up with 12 two-seated tables evenly spaced within lab benches that project from the walls. The front of the room has a white board and large desk with a computer for teacher use and student use when permitted. There is a projector in front of the desk which allows for many opportunities to display notes, diagrams, pictures, etc. For purposes in this lesson students will only use their desk area.
Materials
Pencil
Paper
Projector
Radiometric dating projection (artifact in notes)
Penny Lab:
-50 pennies (per pair)
(Ask students to bring in pennies a week before lesson, too...just in case.)
(penny jar from home...I have tons of them) What is your plan for accumulating these pennies?
-50 paperclips (per pair)
-12 boxes (shoe box, tupperware, any wide container with a lid)
-Data sheet for lab
After completion of this lesson students will:
1) be able to state the age of the earth and explain its formation
2) explain the process of radiometric dating and what it is used for
3) create a model of how radioactive isotopes work in the "Penny Lab"
3) explain the endosymbionic theory and describe the features of the cell types
Instruction:
Opening:
1) Written on board will be "how do you think the earth was formed? how old do you think the earth might be? what do you think the first lifeforms were?" Students will be asked to write a response on a blank piece of paper.
2) As students finish their responses begin asking them to share their answers. Ask, "Is it even important to know how old the earth is? Why? Why not?" (answer should be "yes" because time tells us how much has changed and how long it has taken for these changes to occur.)
3) While discussing, ask students how they think the age of earth was determined (give hints by asking, "what do you think existed before life?" "was there anything before life?). (Rocks, fossils, water, minerals, elements, sun, moon)
4) "Do you think life began small, medium, or large? What do you think it came from?"
5) "By the end of class today you should be able to answer how and when the earth was formed, how can we determine the age of something that is not living, and how and when living things came to be on this planet." Nice that you're trying to activate and assess prior knowledge.
What if they don't know about isotopes?
How did life begin? How will you set up (preveiw, establish importance of) lesson activities?
Engagement:
Mini-lecture How Do We Know when Earth began?
1) Set up the projector with bulleted points as notes students need to write in their notebooks.
2) As notes are discussed remind students that everything is made up of elements, and different combinations of elements make different material (use 2 hydrogen atoms and one oxygen atom makes 1 water molecule).
3) Ask, "what elements do you think rocks are made out of since we have decided that they were around before living organisms?" (Explain that uranium is an element found in some types of rocks and scientists have found a way to use it that helps determine how long ago earth began.)
4) Uranium-235 and U-238 are unstable isotopes of uranium because they have more neutrons than protons. An isotope is a form of the element that has the same number of protons, but a differerent number of neutrons. U-235 and U-238 are radioactive isotopes that are constantly shooting off particles to reach an equal number of protons and neutrons. When an isotope has lost (decay) half its original sample size this time frame is known as an isotope's half life. The half lifes of many isotopes have been determined based on the ratios with the stable form. The half lives of these isotopes have been used to determine the age of the earth because the amount of decay shows how long they have been around. The oldest dated rocks are ~4.4 billion years old, so the estimate for earth's formation is slightly older than that ~ 4.6 byrs.
5) "Now that we have an idea of how old the earth is and the methods that were used to determine it, we are going to do our own experiment that should help explain how radioactive isotopes work and why the half-lives of different isotopes are used to figure out the age of something."
It looks like you are planning to do three main activities: A minilecture, a lab, and a post lab discussion. Each activity requires you to let the students know what they will be doing, why they are doing it, and how the activity will contribute to their knowledge of the unit's topic. Please fill in this lesson with that level of detail.
"When an isotope reaches its half-life, this means that half of the original sample of the isotope is gone. Isotopes like U-238 and U-235 have different half-lives because U-238 is heavier and it takes more time for half of it to decay. There are many isotopes like this, which is why different isotopes are appropriate for determining the ages of living and non-living matter. In the lab we are about to do each pair has an isotope of an unknown element. Your job is to determine the isotope's half-life and explain how this could be use to tell how how long an element has been around."
Penny Lab:
By the end of this lab I want you answer the following questions:
- what do the 50 pennies represent?
- why are the heads up pennies being replaced with paper clips?
- how is this experiment a model of what happens in elements over time?
- based on class data can you determine which elements are heavier and which would be used to date older/younger material?
Procedure:
1) Students partner up with a shoe box, 50 pennies, 50 paper clips, a data sheet and a recording tool (pen/pencil)
2) Put the 50 pennies in the box and shake. Cover with lid and shake the box
3) Replace each heads up penny with a paper clip.
4) Record the number of pennies left in the box.
5) Repeat this process 5 times.
Do you really want them to do this as a procedure with no purpose? Will you frame it with a question? Why not explain to them that they are modeling what happens in very heavy atoms over time? Will you ask them to make a prediction?
Post-lab discussion:
1) Re-group and discuss. Many students may need clarification because groups will more than likely have different results, emphasizing that the idea that each pair had a different isotope of an unknown element.
2) Re-iterate that different results equal different elements or different isotopes and the number of pennies left with each shake is based on the isotope's rate of decay. Each shake of the box represents the isotope getting closer to its half life. Based on each pair's results, about half of the pennies should be left after a number of shakes. Each half life (shake) less and less of the pennies are available to decay (be flipped). Flipped pennies represent the released particles from the nuclei bringing it closer to stability.
3) "Based on what you have learned today how have radioactive isotopes helped determine the age of the earth? Do you think they can be useful for explaining what, when and where different material was on earth?"
Part II:
(may carry over into next lesson)
"How can elements be used to tell how old something is?"
"What can elements be found in? Living? Non-living?" (everything is made up of elements usually in several combinations to make larger and more complex molecules)
1) Re-iterate how isotopes of several elements can be used for dating. Carbon-14 is the most common isotope for dating living things.
"Based on what we have seen with elements of high atomic number like uranium, what do you think the half-life of an element like carbon would be?"
(5,730 years for C-14)
"Do you think scientists used carbon half-life to determine when life first appeared?" (no, scientists use fossils of what appear to be cells and the sample size of elements in the fossil)
"What is one basic thing that all living things are composed of ?" (proteins)
"What makes some cells more complex than others?" (nucleus, chloroplasts, mitochondria, etc...)
2) Put up transparency of proakryotic cell, plant cell, animal cell, ask students to point out some of the differences.
3) When the first living things appeared they were prokaryotic single cells, living in the prehistoric sea. (p 284-290)
Jigsaw Activity
1) Students will be split into six groups to read and write major points of their assigned section in p-284-290
2) Students will be given 10 minutes to read their section and assign a reporter to share out their findings in each section.
3) As each group shares out each individual will be accountable for the notes they take by handing them in at the end of class (artifact).
4) The last group will have endosymbiosis. Ask if anyone can see how this theory fits into what we have learned about cell structures
" What do you think endosymbiosis has to do with the diversity of organisms today?"
"Could you propose any other option for how life began?"
"What was believed before this theory was proposed?"
State that this is the first living model of evolution. Evolution in biology is change in form, function, or structure over time.
Closure:
1) At about 10 minutes to class end wrap up discussion and have students re-read their responses.
2) Return to opening response question and review students answers. Have them add onto their reponses based on what was learned about endosymbiosis and radiometric dating.
3) Do 1, 2 punch with students on a notecard. This will be their ticket for leaving class.
(1,2 punch= 1 thing you knew that helped you understand today's lesson, 1 thing you learned in this lesson, and 1 thing you still don't understand or want to know more about)
Assessment:
Collect and read opening responses for students that finished revisions.
Collect and read notes based on what students gathered from jigsaw activity.
be sure to return notes and responses by next lesson so students can have resources to study
Assign revisions as homework for those who don't finish.
Review responses and plan accordingly to address misconceptions or concepts that students seem very clear about.
Read exit tickets and decide if next lesson needs to be altered to address common questions or misconceptions
Lesson Plan
Lesson Title:
Origins of LifeState Standards: GLEs/GSEs
ESS1 4aa-calculating the age of rocks from various regions using radioactive half life (given its constituent elements, isotopes and rate of decay)and using those values to provide evidence for geological relationships between/among regions.LS3 8c-recognizing patterns in molecular and fossil evidence, to provide a scientific explanation for Natural Selection and its evolutionary consequences.
National Standards:
Standard A- the ability to DO scientific inquiryStandard D- ESS3-origin and evolution of the earth system
Context of Lesson:
This lesson will teach students about how the earth was formed and when and how the first forms of life developed. The points of the lesson are: 1) the age of the earth has been dated using radioactive isotopes, like uranium-238; 2) elements can be used to determine the changing composition of earth and the time that they were formed; 3) the earliest life-forms were single celled organisms that gave rise to other organisms through endosymbiosisOpportunities to Learn:
Depth of Knowledge:
DOK-level 1: recall and reproduction of the age of earth and the procedure used to figure it outDOK-level 1: recall and reproduction of plant and animal cell structure and function
DOK-level 3: connecting the state of prehistoric cells to current cells
DOK-level 2: interpret how penny lab represent the actions of radioactive isotopes
Prerequisite Knowledge:
-"Big Bang" theory-rock cycles
-gravitational pull
-cellular structures and functions
Plans for Differentiating Instruction
Bodily-kinesthetic: Penny lab is a hands-on activity (shaking the box, picking up pennies, using more than a pencil and paper)Visual: Diagram of prehistoric cells next to modern cells so students can see the similarities and differences
Accommodations and modifications
Students with poor vision will have priority seating for viewing the overhead. Students with documented learning disabilities will receive the handouts one class day before the lesson.Environmental factors
The classroom is set up with 12 two-seated tables evenly spaced within lab benches that project from the walls. The front of the room has a white board and large desk with a computer for teacher use and student use when permitted. There is a projector in front of the desk which allows for many opportunities to display notes, diagrams, pictures, etc. For purposes in this lesson students will only use their desk area.Materials
PencilPaper
Projector
Radiometric dating projection (artifact in notes)
Penny Lab:
-50 pennies (per pair)
(Ask students to bring in pennies a week before lesson, too...just in case.)
(penny jar from home...I have tons of them) What is your plan for accumulating these pennies?
-50 paperclips (per pair)
-12 boxes (shoe box, tupperware, any wide container with a lid)
-Data sheet for lab
Diagram of current plant and animal cells
Diagram of prehistoric cells
Objectives:
After completion of this lesson students will:1) be able to state the age of the earth and explain its formation
2) explain the process of radiometric dating and what it is used for
3) create a model of how radioactive isotopes work in the "Penny Lab"
3) explain the endosymbionic theory and describe the features of the cell types
Instruction:
Opening:
1) Written on board will be "how do you think the earth was formed? how old do you think the earth might be? what do you think the first lifeforms were?" Students will be asked to write a response on a blank piece of paper.2) As students finish their responses begin asking them to share their answers. Ask, "Is it even important to know how old the earth is? Why? Why not?" (answer should be "yes" because time tells us how much has changed and how long it has taken for these changes to occur.)
3) While discussing, ask students how they think the age of earth was determined (give hints by asking, "what do you think existed before life?" "was there anything before life?). (Rocks, fossils, water, minerals, elements, sun, moon)
4) "Do you think life began small, medium, or large? What do you think it came from?"
5) "By the end of class today you should be able to answer how and when the earth was formed, how can we determine the age of something that is not living, and how and when living things came to be on this planet."
Nice that you're trying to activate and assess prior knowledge.
What if they don't know about isotopes?
How did life begin?
How will you set up (preveiw, establish importance of) lesson activities?
Engagement:
Mini-lectureHow Do We Know when Earth began?
1) Set up the projector with bulleted points as notes students need to write in their notebooks.
2) As notes are discussed remind students that everything is made up of elements, and different combinations of elements make different material (use 2 hydrogen atoms and one oxygen atom makes 1 water molecule).
3) Ask, "what elements do you think rocks are made out of since we have decided that they were around before living organisms?" (Explain that uranium is an element found in some types of rocks and scientists have found a way to use it that helps determine how long ago earth began.)
4) Uranium-235 and U-238 are unstable isotopes of uranium because they have more neutrons than protons. An isotope is a form of the element that has the same number of protons, but a differerent number of neutrons. U-235 and U-238 are radioactive isotopes that are constantly shooting off particles to reach an equal number of protons and neutrons. When an isotope has lost (decay) half its original sample size this time frame is known as an isotope's half life. The half lifes of many isotopes have been determined based on the ratios with the stable form. The half lives of these isotopes have been used to determine the age of the earth because the amount of decay shows how long they have been around. The oldest dated rocks are ~4.4 billion years old, so the estimate for earth's formation is slightly older than that ~ 4.6 byrs.
5) "Now that we have an idea of how old the earth is and the methods that were used to determine it, we are going to do our own experiment that should help explain how radioactive isotopes work and why the half-lives of different isotopes are used to figure out the age of something."
It looks like you are planning to do three main activities: A minilecture, a lab, and a post lab discussion. Each activity requires you to let the students know what they will be doing, why they are doing it, and how the activity will contribute to their knowledge of the unit's topic. Please fill in this lesson with that level of detail.
"When an isotope reaches its half-life, this means that half of the original sample of the isotope is gone. Isotopes like U-238 and U-235 have different half-lives because U-238 is heavier and it takes more time for half of it to decay. There are many isotopes like this, which is why different isotopes are appropriate for determining the ages of living and non-living matter. In the lab we are about to do each pair has an isotope of an unknown element. Your job is to determine the isotope's half-life and explain how this could be use to tell how how long an element has been around."
Penny Lab:
By the end of this lab I want you answer the following questions:
- what do the 50 pennies represent?
- why are the heads up pennies being replaced with paper clips?
- how is this experiment a model of what happens in elements over time?
- based on class data can you determine which elements are heavier and which would be used to date older/younger material?
Procedure:
1) Students partner up with a shoe box, 50 pennies, 50 paper clips, a data sheet and a recording tool (pen/pencil)
2) Put the 50 pennies in the box and shake. Cover with lid and shake the box
3) Replace each heads up penny with a paper clip.
4) Record the number of pennies left in the box.
5) Repeat this process 5 times.
Do you really want them to do this as a procedure with no purpose? Will you frame it with a question? Why not explain to them that they are modeling what happens in very heavy atoms over time? Will you ask them to make a prediction?
Post-lab discussion:
1) Re-group and discuss. Many students may need clarification because groups will more than likely have different results, emphasizing that the idea that each pair had a different isotope of an unknown element.
2) Re-iterate that different results equal different elements or different isotopes and the number of pennies left with each shake is based on the isotope's rate of decay. Each shake of the box represents the isotope getting closer to its half life. Based on each pair's results, about half of the pennies should be left after a number of shakes. Each half life (shake) less and less of the pennies are available to decay (be flipped). Flipped pennies represent the released particles from the nuclei bringing it closer to stability.
3) "Based on what you have learned today how have radioactive isotopes helped determine the age of the earth? Do you think they can be useful for explaining what, when and where different material was on earth?"
Part II:
(may carry over into next lesson)
"How can elements be used to tell how old something is?"
"What can elements be found in? Living? Non-living?" (everything is made up of elements usually in several combinations to make larger and more complex molecules)
1) Re-iterate how isotopes of several elements can be used for dating. Carbon-14 is the most common isotope for dating living things.
"Based on what we have seen with elements of high atomic number like uranium, what do you think the half-life of an element like carbon would be?"
(5,730 years for C-14)
"Do you think scientists used carbon half-life to determine when life first appeared?" (no, scientists use fossils of what appear to be cells and the sample size of elements in the fossil)
"What is one basic thing that all living things are composed of ?" (proteins)
"What makes some cells more complex than others?" (nucleus, chloroplasts, mitochondria, etc...)
2) Put up transparency of proakryotic cell, plant cell, animal cell, ask students to point out some of the differences.
3) When the first living things appeared they were prokaryotic single cells, living in the prehistoric sea. (p 284-290)
Jigsaw Activity
1) Students will be split into six groups to read and write major points of their assigned section in p-284-290
2) Students will be given 10 minutes to read their section and assign a reporter to share out their findings in each section.
3) As each group shares out each individual will be accountable for the notes they take by handing them in at the end of class (artifact).
4) The last group will have endosymbiosis. Ask if anyone can see how this theory fits into what we have learned about cell structures
" What do you think endosymbiosis has to do with the diversity of organisms today?"
"Could you propose any other option for how life began?"
"What was believed before this theory was proposed?"
State that this is the first living model of evolution. Evolution in biology is change in form, function, or structure over time.
Closure:
1) At about 10 minutes to class end wrap up discussion and have students re-read their responses.2) Return to opening response question and review students answers. Have them add onto their reponses based on what was learned about endosymbiosis and radiometric dating.
3) Do 1, 2 punch with students on a notecard. This will be their ticket for leaving class.
(1,2 punch= 1 thing you knew that helped you understand today's lesson, 1 thing you learned in this lesson, and 1 thing you still don't understand or want to know more about)
Assessment:
Collect and read opening responses for students that finished revisions.Collect and read notes based on what students gathered from jigsaw activity.
be sure to return notes and responses by next lesson so students can have resources to study
Assign revisions as homework for those who don't finish.
Review responses and plan accordingly to address misconceptions or concepts that students seem very clear about.
Read exit tickets and decide if next lesson needs to be altered to address common questions or misconceptions
Reflections
(only done after lesson is enacted)Student Work Sample 1 – Approaching Proficiency:
Student Work Sample 2 – Proficient:
Student Work Sample 3 – Exceeds Proficiency:
Evolution Home